Hi Troy,
Welcome to WikiTree.
Since the profile for Walker Seal have a security level of "Public", not "Open" you'll need to ask the Profile Manager, Josh Varnado, to put you on the trusted listed. Look on the far right column of Walker Seal's profile page, there's a "Collaboration" topic. Under this topic is a "Request to join this profile's Trusted List " which will take you to where you need to go.
After this has been accomplished by Josh, you will be able to edit the profile and add the generations needed to link you up.
If you want additional guidance, let us know and we'll give you more help. There's also a lot of written HELP such as https://www.wikitree.com/wiki/Help:How_to_Get_Started_with_Genealogy#Begin_Building_Your_Family_Tree
I noticed there aren't any sources on Walker's profile yet. Don't forget to add your sources as soon as possible, you'll find it's helpful as you are building your profiles.
EDIT: If you're not certain you have a relationship with Walker Adolphus Seal, sources and your research should answer this question for you.